There has been a growing interest in the mass production of contact lenses from a lens-forming composition comprising at least one polymerizable/crosslinkable polymeric material. For example, various water-soluble, actinically-crosslinkable prepolymers (e.g., those disclosed in U.S. Pat. Nos. 5,508,317, 5,583,163, 5,665,840, 5,712,356, 5,789,464, 5,849,841, 5,849,810, 6,165,408, 6,221,303, 6,303,687, 6,479,587, in U.S. patent Application Publication No. 2004/0082680A1, in EP 932,635, and in PCT patent application WO 2000/31150, herein incorporated by references in their entireties) have been developed as starting materials for producing hydrogel contact lenses at considerably low cost according to a fast, highly efficient contact lens manufacturing process disclosed in U.S. Pat. Nos. 5,508,317, 5,583,163, 5,789,464 and 5,849,810. Other examples include without limitation macromers developed as one of starting materials for making silicone hydrogel contact lenses (e.g., lotrafilicon A, lotrafilcon B, balafilcon A, galyfilcon A, senofilcon A, etc.). So far, preparation of those polymerizable/crosslinkable polymeric materials is carried out manually or semi-manually in a batch or semi-batch process. However, synthesis of those polymerizable/crosslinkable polymeric materials may represent a considerable risk to people and the environment due to use of a relatively large amount of highly toxic chemical substances. Furthermore, synthesis of those polymeric materials requires strict adherence to numerous reaction conditions (e.g., temperature, reactant concentrations, uniform local concentration profile of reactants, reaction time in a reactor, pressure, reaction medium, etc.). Batch or semi-batch polymerization technologies inherently have a great difficulty in ensuring uniform product quality and consistency in product quality between batch preparations. Therefore, there is a need for a continuous process for producing polymerizable/crosslinkable polymeric materials in a simple, reproducible, and highly-controllable manner with increased safety for humans and the environment and with good yields.
The objects of the invention therefore are to provide systems and methods for performing polymerization or copolymerization in a continuous-flow, reproducible, and highly-controllable manner with increased safety for humans and the environment and with good yields.